Unexpected behavior from simple shell in C Debian Linux -

the following code:

#include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <string.h>  #define max_line 80 /* max command length */  int main(void) {    char fullcmd[max_line-1];    const char *exit_cmd = "exit"; /* command exit shell */    int should_run = 1; /* flag determine when exit*/     while (should_run)    {       printf("daw.0>");       fflush(stdout);       scanf("%s", fullcmd);        if (strcmp(fullcmd, exit_cmd) == 0)       {          should_run = 0;       }    }    return 0; } 

results in prompt (daw.0>) printing out repeatedly (the number of words - 1 times). example, i type in "hello there everyone, how you?", following output seen:

daw.0>hello there everyone, how you?  daw.0> daw.0> daw.0> daw.0> daw.0> daw.0> 

i don't understand why. have lot more need create shell assignment, can't simplest variation work reliably. using debian distribution of linux in virtual box.

scanf() %s stops scanning @ first whitespace. explains behaviour observe.

what wanted use fgets(). aware fgets() reads in newline if there's sufficient space available in buffer. if don't want have remove trailing newline (if any).